21 March 1970
Nicholas Courtney (Brigadier Lethbridge-Stewart), Ronald Allen (Ralph Cornish), Robert Cawdron (Taltalian) [1-2,4], John Abineri (Carrington / General Carrington)†, Ric Felgate (Van Lyden) [1-3,6], Michael Wisher (John Wakefield) [1-2,7], Cheryl Molineaux (Miss Rutherford) [1-2], Ray Armstrong (Grey) [1-2], Robert Robertson (Collinson) [1-2], Dallas Cavell (Quinlan) [2-5], Bernard Martin , Joanna Ross [5-7], Carl Conway [5-6] (Control Room Assistant), Juan Moreno (Dobson) , James Haswell (Corporal Champion) , Derek Ware (Unit Sergeant) , William Dysart (Reegan) [3-7], Cyril Shaps (Lennox) [3-5], Gordon Sterne (Heldorf) , Steve Peters [3-5,7], Neville Simons [3-5,7], Ric Felgate [4-5,7] (Astronauts), Max Faulkner (Unit Soldier) , John Lord (Masters) , Tony Harwood (Flynn) , John Levene (Sergeant Benton) [5,7], James Clayton (Private Parker) , Roy Scammell (Technician) , Peter Noel Cook (Alien Space Captain) [6-7], Peter Halliday (Aliens’ Voices) [6-7], Steve Peters (Lefee) , Neville Simons (Michaels) , Geoffrey Beevers (Private Johnson) .
|Written by||David Whitaker|
|Directed by||Michael Ferguson|
|Produced by||Barry Letts|
When all communication is lost from Mars Probe 7 shortly after it leaves Mars and begins its trip back to Earth, a second craft is launched to investigate. As Recovery 7 docks in space, it too loses all communication…
The Doctor and UNIT are given the task of investigating the mystery, as Recovery 7 returns to Earth. It appears that no one can be trusted, as the space capsule is hijacked from its UNIT convoy with military precision. What has happened to the missing astronauts? Could this be a secret invasion from Mars, or is the enemy much closer to home?
As the Doctor plans a daring space mission of his own, his assistant Liz Shaw goes missing. Who is working against UNIT in order to bring mankind into conflict with an alien race…?
- At the start of the adventure, the Doctor has not yet forgiven the Brigadier for his destruction of the Silurian base.
- The Doctor is fixing the TARDIS‘ Time Vector Generator, which sends Liz fifteen seconds into the future.
- The Doctor and Liz receive data from real life radio telescopes: Haystack Observatory and Catalina in the US, Algonquin in Canada, Arecibo in Puerto Rico,
- Mullard Radio Astronomy Observatory (“Cambridge”) in the UK, Culgoora in Australia, Dwingeloo in Holland, Nancay in France, and Onsala in Sweden.
- The Doctor can make solid objects vanish and, a few minutes later, reappear — a method he refers to as “transmigration of object”. This is the first story to feature Benton with the rank of Sergeant.
- Liz can speak French.
- The aliens are not native Martians.
- The aliens‘ radioactivity is suggested as being conductible like electricity.
- General Carrington suggests sarcastically that the Doctor has nine lives.
- Carrington uses the Military Police to arrest the Brigadier and his men.